How do I disable the tracking and display of recently opened files (and whatever else is remembered) in a default installation of Ubuntu 11.10?

(Note that this is not a duplicate of How can I keep recent files from appearing in Unity?, since that question and its answers are concerned with temporary and specific filtering. I want to disable it completely for a single user account.)

Okay, to deflect the inevitable and expand on my motivation...

While trawling the usual forums and Google results for a solution, it (unsurprisingly) seems that the near-universal use cases for this request are either browsing porn or Warhammer research. And the obvious solution to this is to create another user account to contain all evidence.

However, this is not why I'm asking, and I don't say that to get all high and mighty about it, it's because this answer won't help. (Even though I really don't have any interest in Warhammer, and I have no idea how that paint pot and brush ended up in my drawer, no that's not glue on my thumb, etc.)

My actual use case is that I use my personal laptop for presentations in different circles of my life. I have a user account set up with all the settings I like for presentations (shortcuts, small launcher, default associations, etc). But I don't want an accidental keystroke (or the find dialog) to display other recent presentations I've given, or the files I used in composing the presentation, or whatever. I also don't want to have to recreate this profile for every single presentation I might give. I just want a nice little isolated, memoryless, clean corner of my notebook for public display.